--- /dev/null
+/*
+ * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * 16550-compatible UART
+ *
+ */
+
+#include <errno.h>
+#include <ipxe/uart.h>
+
+/** UART port bases */
+static uint16_t uart_base[] = {
+ [COM1] = 0x3f8,
+ [COM2] = 0x2f8,
+ [COM3] = 0x3e8,
+ [COM4] = 0x2e8,
+};
+
+/**
+ * Select UART port
+ *
+ * @v uart UART
+ * @v port Port number, or 0 to disable
+ * @ret rc Return status code
+ */
+int uart_select ( struct uart *uart, unsigned int port ) {
+
+ /* Clear UART base */
+ uart->base = NULL;
+
+ /* Set new UART base */
+ if ( port < ( sizeof ( uart_base ) / sizeof ( uart_base[0] ) ) ) {
+ uart->base = ( ( void * ) ( intptr_t ) uart_base[port] );
+ return 0;
+ } else {
+ return -ENODEV;
+ }
+}
#define ERRFILE_timer_bios ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00010000 )
#define ERRFILE_hvm ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00020000 )
#define ERRFILE_hyperv ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00030000 )
+#define ERRFILE_x86_uart ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00040000 )
#define ERRFILE_cpuid_cmd ( ERRFILE_ARCH | ERRFILE_OTHER | 0x00000000 )
#define ERRFILE_cpuid_settings ( ERRFILE_ARCH | ERRFILE_OTHER | 0x00010000 )
--- /dev/null
+#ifndef _BITS_UART_H
+#define _BITS_UART_H
+
+/** @file
+ *
+ * 16550-compatible UART
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/io.h>
+
+/**
+ * Write to UART register
+ *
+ * @v uart UART
+ * @v addr Register address
+ * @v data Data
+ */
+static inline __attribute__ (( always_inline )) void
+uart_write ( struct uart *uart, unsigned int addr, uint8_t data ) {
+ outb ( data, ( uart->base + addr ) );
+}
+
+/**
+ * Read from UART register
+ *
+ * @v uart UART
+ * @v addr Register address
+ * @ret data Data
+ */
+static inline __attribute__ (( always_inline )) uint8_t
+uart_read ( struct uart *uart, unsigned int addr ) {
+ return inb ( uart->base + addr );
+}
+
+extern int uart_select ( struct uart *uart, unsigned int port );
+
+#endif /* _BITS_UART_H */
--- /dev/null
+/*
+ * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * 16550-compatible UART
+ *
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <ipxe/uart.h>
+
+/** Timeout for transmit holding register to become empty */
+#define UART_THRE_TIMEOUT_MS 100
+
+/** Timeout for transmitter to become empty */
+#define UART_TEMT_TIMEOUT_MS 1000
+
+/**
+ * Transmit data
+ *
+ * @v uart UART
+ * @v data Data
+ */
+void uart_transmit ( struct uart *uart, uint8_t data ) {
+ unsigned int i;
+ uint8_t lsr;
+
+ /* Wait for transmitter holding register to become empty */
+ for ( i = 0 ; i < UART_THRE_TIMEOUT_MS ; i++ ) {
+ lsr = uart_read ( uart, UART_LSR );
+ if ( lsr & UART_LSR_THRE )
+ break;
+ mdelay ( 1 );
+ }
+
+ /* Transmit data (even if we timed out) */
+ uart_write ( uart, UART_THR, data );
+}
+
+/**
+ * Flush data
+ *
+ * @v uart UART
+ */
+void uart_flush ( struct uart *uart ) {
+ unsigned int i;
+ uint8_t lsr;
+
+ /* Wait for transmitter and receiver to become empty */
+ for ( i = 0 ; i < UART_TEMT_TIMEOUT_MS ; i++ ) {
+ uart_read ( uart, UART_RBR );
+ lsr = uart_read ( uart, UART_LSR );
+ if ( ( lsr & UART_LSR_TEMT ) && ! ( lsr & UART_LSR_DR ) )
+ break;
+ }
+}
+
+/**
+ * Initialise UART
+ *
+ * @v uart UART
+ * @v baud Baud rate, or zero to leave unchanged
+ * @v lcr Line control register value, or zero to leave unchanged
+ * @ret rc Return status code
+ */
+int uart_init ( struct uart *uart, unsigned int baud, uint8_t lcr ) {
+ uint8_t dlm;
+ uint8_t dll;
+
+ /* Check for existence of UART */
+ if ( ! uart->base )
+ return -ENODEV;
+ uart_write ( uart, UART_SCR, 0x18 );
+ if ( uart_read ( uart, UART_SCR ) != 0x18 )
+ return -ENODEV;
+ uart_write ( uart, UART_SCR, 0xae );
+ if ( uart_read ( uart, UART_SCR ) != 0xae )
+ return -ENODEV;
+
+ /* Configure divisor and line control register, if applicable */
+ if ( ! lcr )
+ lcr = uart_read ( uart, UART_LCR );
+ uart->lcr = lcr;
+ uart_write ( uart, UART_LCR, ( lcr | UART_LCR_DLAB ) );
+ if ( baud ) {
+ uart->divisor = ( UART_MAX_BAUD / baud );
+ dlm = ( ( uart->divisor >> 8 ) & 0xff );
+ dll = ( ( uart->divisor >> 0 ) & 0xff );
+ uart_write ( uart, UART_DLM, dlm );
+ uart_write ( uart, UART_DLL, dll );
+ } else {
+ dlm = uart_read ( uart, UART_DLM );
+ dll = uart_read ( uart, UART_DLL );
+ uart->divisor = ( ( dlm << 8 ) | dll );
+ }
+ uart_write ( uart, UART_LCR, ( lcr & ~UART_LCR_DLAB ) );
+
+ /* Disable interrupts */
+ uart_write ( uart, UART_IER, 0 );
+
+ /* Enable FIFOs */
+ uart_write ( uart, UART_FCR, UART_FCR_FE );
+
+ /* Assert DTR and RTS */
+ uart_write ( uart, UART_MCR, ( UART_MCR_DTR | UART_MCR_RTS ) );
+
+ /* Flush any stale data */
+ uart_flush ( uart );
+
+ return 0;
+}
#define ERRFILE_i2c_bit ( ERRFILE_DRIVER | 0x00120000 )
#define ERRFILE_spi_bit ( ERRFILE_DRIVER | 0x00130000 )
#define ERRFILE_nvsvpd ( ERRFILE_DRIVER | 0x00140000 )
+#define ERRFILE_uart ( ERRFILE_DRIVER | 0x00150000 )
#define ERRFILE_3c509 ( ERRFILE_DRIVER | 0x00200000 )
#define ERRFILE_bnx2 ( ERRFILE_DRIVER | 0x00210000 )
--- /dev/null
+#ifndef _IPXE_UART_H
+#define _IPXE_UART_H
+
+/** @file
+ *
+ * 16550-compatible UART
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+
+/** Transmitter holding register */
+#define UART_THR 0x00
+
+/** Receiver buffer register */
+#define UART_RBR 0x00
+
+/** Interrupt enable register */
+#define UART_IER 0x01
+
+/** FIFO control register */
+#define UART_FCR 0x02
+#define UART_FCR_FE 0x01 /**< FIFO enable */
+
+/** Line control register */
+#define UART_LCR 0x03
+#define UART_LCR_WLS0 0x01 /**< Word length select bit 0 */
+#define UART_LCR_WLS1 0x02 /**< Word length select bit 1 */
+#define UART_LCR_STB 0x04 /**< Number of stop bits */
+#define UART_LCR_PEN 0x08 /**< Parity enable */
+#define UART_LCR_EPS 0x10 /**< Even parity select */
+#define UART_LCR_DLAB 0x80 /**< Divisor latch access bit */
+
+#define UART_LCR_WORD_LEN(x) ( ( (x) - 5 ) << 0 ) /**< Word length */
+#define UART_LCR_STOP_BITS(x) ( ( (x) - 1 ) << 2 ) /**< Stop bits */
+#define UART_LCR_PARITY(x) ( ( (x) - 0 ) << 3 ) /**< Parity */
+
+/**
+ * Calculate line control register value
+ *
+ * @v word_len Word length (5-8)
+ * @v parity Parity (0=none, 1=odd, 3=even)
+ * @v stop_bits Stop bits (1-2)
+ * @ret lcr Line control register value
+ */
+#define UART_LCR_WPS( word_len, parity, stop_bits ) \
+ ( UART_LCR_WORD_LEN ( (word_len) ) | \
+ UART_LCR_PARITY ( (parity) ) | \
+ UART_LCR_STOP_BITS ( (stop_bits) ) )
+
+/** Default LCR value: 8 data bits, no parity, one stop bit */
+#define UART_LCR_8N1 UART_LCR_WPS ( 8, 0, 1 )
+
+/** Modem control register */
+#define UART_MCR 0x04
+#define UART_MCR_DTR 0x01 /**< Data terminal ready */
+#define UART_MCR_RTS 0x02 /**< Request to send */
+
+/** Line status register */
+#define UART_LSR 0x05
+#define UART_LSR_DR 0x01 /**< Data ready */
+#define UART_LSR_THRE 0x20 /**< Transmitter holding register empty */
+#define UART_LSR_TEMT 0x40 /**< Transmitter empty */
+
+/** Scratch register */
+#define UART_SCR 0x07
+
+/** Divisor latch (least significant byte) */
+#define UART_DLL 0x00
+
+/** Divisor latch (most significant byte) */
+#define UART_DLM 0x01
+
+/** Maximum baud rate */
+#define UART_MAX_BAUD 115200
+
+/** A 16550-compatible UART */
+struct uart {
+ /** I/O port base address */
+ void *base;
+ /** Baud rate divisor */
+ uint16_t divisor;
+ /** Line control register */
+ uint8_t lcr;
+};
+
+/** Symbolic names for port indexes */
+enum uart_port {
+ COM1 = 1,
+ COM2 = 2,
+ COM3 = 3,
+ COM4 = 4,
+};
+
+#include <bits/uart.h>
+
+void uart_write ( struct uart *uart, unsigned int addr, uint8_t data );
+uint8_t uart_read ( struct uart *uart, unsigned int addr );
+int uart_select ( struct uart *uart, unsigned int port );
+
+/**
+ * Check if received data is ready
+ *
+ * @v uart UART
+ * @ret ready Data is ready
+ */
+static inline int uart_data_ready ( struct uart *uart ) {
+ uint8_t lsr;
+
+ lsr = uart_read ( uart, UART_LSR );
+ return ( lsr & UART_LSR_DR );
+}
+
+/**
+ * Receive data
+ *
+ * @v uart UART
+ * @ret data Data
+ */
+static inline uint8_t uart_receive ( struct uart *uart ) {
+
+ return uart_read ( uart, UART_RBR );
+}
+
+extern void uart_transmit ( struct uart *uart, uint8_t data );
+extern void uart_flush ( struct uart *uart );
+extern int uart_init ( struct uart *uart, unsigned int baud, uint8_t lcr );
+
+#endif /* _IPXE_UART_H */
projects / thirdparty / ipxe.git / commitdiff
